JeffBeall
asked on
java programming
I am just starting to learn java programming and have a website with a tutorial/walk-through on learning how to code in java.
I downloaded jdk-7u3-windows-x64.exe and it installed without a problem, I am working on a windows 7 box.
I'm at a point where I am trying to set my Path and ClassPath, so I go to the environment variables and create a new variable for java. I have a screen shot.
but at a command prompt, if I type
java
it works fine, but if I type
javac
I get
"'javac' is not recognized as an internal or external command,
operable program or batch file."
I think this might be related to the error I get when I try to run the first "program" the tutorial gives. here is the code
public class MyProgram {
public static void main(String[] args) {
System.out.println(
"Eureka, I can put Java on my resume.");
}
}
It compiles fine if at the command prompt I go to the javac path,
C:\Program Files\Java\jdk1.7.0_03\bin
and it makes
MyProgram.class
but when I run
java MyProgram.class
I get
"Error: Could not find or load main class c:\javacode\MyProgram.clas s"
I don't get what I'm doing wrong?
Any ideas?
I downloaded jdk-7u3-windows-x64.exe and it installed without a problem, I am working on a windows 7 box.
I'm at a point where I am trying to set my Path and ClassPath, so I go to the environment variables and create a new variable for java. I have a screen shot.
but at a command prompt, if I type
java
it works fine, but if I type
javac
I get
"'javac' is not recognized as an internal or external command,
operable program or batch file."
I think this might be related to the error I get when I try to run the first "program" the tutorial gives. here is the code
public class MyProgram {
public static void main(String[] args) {
System.out.println(
"Eureka, I can put Java on my resume.");
}
}
It compiles fine if at the command prompt I go to the javac path,
C:\Program Files\Java\jdk1.7.0_03\bin
and it makes
MyProgram.class
but when I run
java MyProgram.class
I get
"Error: Could not find or load main class c:\javacode\MyProgram.clas
I don't get what I'm doing wrong?
Any ideas?
Normally you should make sure that C:\Program Files\Java\jdk1.7.0_03\bin is in your PATH
(not javapath but PATH)
(not javapath but PATH)
Best of all make it so that your PATH
begins with
C:\Program Files\Java\jdk1.7.0_03\bin
begins with
C:\Program Files\Java\jdk1.7.0_03\bin
Then go to any folder, copy over to that folder your file
MyProgram.java
and then type
javac MyProgram.java
and then
java MyProgram
it shouild work
MyProgram.java
and then type
javac MyProgram.java
and then
java MyProgram
it shouild work
Mind, that after you change PATH in your co ntrol-panel environement you need to open a new dos window (after youchanged the PATH to opne window - not before)
This is the best practice way of setting things:
a. define JAVA_HOME as C:\Program Files\Java\jdk1.7.0_03
b. If your only jdk, append the following to PATH
%JAVA_HOME%\bin
If you need a classpath at all, it's usually better to do that at the beginning of your session
a. define JAVA_HOME as C:\Program Files\Java\jdk1.7.0_03
b. If your only jdk, append the following to PATH
%JAVA_HOME%\bin
If you need a classpath at all, it's usually better to do that at the beginning of your session
The main thing is to pre-pend this :
C:\Program Files\Java\jdk1.7.0_03\bin
to your PATH
You want to perepend it as in majority of cases you'll have some older java in the path and if it comes before it can screw up your oepration
Some special cases require JAVA_HOME but it is rather rare.
The most important thisng is to have your PATH correct
(and there is no such thing as javapath - it is not used - you may remove it)
C:\Program Files\Java\jdk1.7.0_03\bin
to your PATH
You want to perepend it as in majority of cases you'll have some older java in the path and if it comes before it can screw up your oepration
Some special cases require JAVA_HOME but it is rather rare.
The most important thisng is to have your PATH correct
(and there is no such thing as javapath - it is not used - you may remove it)
SOLUTION
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ASKER
"What is c:\javacode and why this folder is mentiooned"
I thought I would put all the so called programs in one place. so I made a folder called javacode on the root of c
I thought I just had to make a new environment variable.
So, I put
C:\Program Files\Java\jdk1.7.0_03\bin
in the path statement, and now javac works.
and I closed all my command prompts, deleted MyProgram.class, re-compiled MyProgram.java
then ran
c:\javacode\java MyProgram.call
but I still get
Error: Could not find or load main class MyProgram.class
I thought I would put all the so called programs in one place. so I made a folder called javacode on the root of c
I thought I just had to make a new environment variable.
So, I put
C:\Program Files\Java\jdk1.7.0_03\bin
in the path statement, and now javac works.
and I closed all my command prompts, deleted MyProgram.class, re-compiled MyProgram.java
then ran
c:\javacode\java MyProgram.call
but I still get
Error: Could not find or load main class MyProgram.class
you need to go to
c:\javacode>
and from that prompt say:
java MyProgram
(without any extension)
c:\javacode>
and from that prompt say:
java MyProgram
(without any extension)
ASKER CERTIFIED SOLUTION
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ASKER
It was the .class extension!!
I ran
java MyProgram
and it worked fine!
Thank you for the help.
I ran
java MyProgram
and it worked fine!
Thank you for the help.
What is c:\javacode and why this folder is mentiooned if you are doing everuthing in
C:\Program Files\Java\jdk1.7.0_03\bin
folder?